What is the type of finishing used when the fabric becomes irregular widthwise after the process of the weaving and washing ?

Question

Accepted Answer

The correct option is 3: Tantering

The correct answer is Tantering. This is a crucial mechanical finishing process designed specifically to address dimensional instability in woven and knitted fabrics, such as the "irregular widthwise" condition mentioned. After weaving, and especially after wet treatments like scouring, washing, or dyeing, the fabric fibers can swell, causing the fabric to distort, shrink, and result in a non-uniform width, or a condition where the crosswise threads (weft) are no longer perpendicular to the lengthwise threads (warp)—a defect known as 'bowing' or 'skewing.' The *tenter frame* (or *stenter*) machine holds the fabric edges firmly with pins or clips and stretches the fabric to a predetermined, uniform width. While held under tension, the fabric passes through a heated chamber to dry and heat-set the fibers, thus stabilizing the material's final width, straightening the grain, and giving it a balanced, smooth appearance, correcting the irregularity caused by earlier processes.

The incorrect option is 1: Calendering

Calendering is a mechanical finishing process that involves passing the fabric through a series of heavy, heated rollers, similar to ironing. The primary purpose of calendering is to improve the fabric's appearance and feel by pressing and flattening the yarns. This process imparts a smooth surface, a high luster or glaze, and can reduce the fabric's thickness. While calendering improves the aesthetic quality of the cloth, it is not used to correct major dimensional instability or irregular width. If a fabric is severely bowed or uneven in width, calendering will not fix the issue and may even permanently set the distortion into the fabric. The focus of calendering is on surface aesthetics, not on the fundamental dimensional geometry of the cloth.

The incorrect option is 2: Stiffening

Stiffening is a chemical finishing treatment applied to fabrics to increase their body, weight, and rigidity. Chemical agents like starch, resins, or special polymers are impregnated into the fabric structure and then dried. This finish is primarily functional and aesthetic, aimed at creating a desired 'hand' or crispness, such as giving a cotton shirt a stiff collar. Stiffening is concerned with the fabric's texture and drapeability, not the correction of its dimensional width or structural straightness. Applying a stiffening agent to a fabric that is already irregular widthwise would merely make the dimensional flaw more rigid and noticeable, not correct it.

The incorrect option is 4: Bleaching

Bleaching is a chemical preparatory process, not a final mechanical finish, and is performed to improve the fabric's whiteness. It involves treating the fabric with oxidizing or reducing agents to remove natural coloring matter and residual impurities. The sole purpose is to prepare the fabric for dyeing, printing, or for a white end-use by making the material clean and uniformly white. Bleaching does not involve any mechanical process to apply tension or adjust the fabric's width. In fact, wet processes like bleaching can often *contribute* to the widthwise irregularities, which the subsequent tentering process is then required to fix.